WhatsApp is reportedly on the verge of adding the most-anticipated voice-calling feature to its popular instant messaging app.

Several reports in the past have indicated that a voice calling feature for WhatsApp may be in the offing. The latest rumour adds more weight to the speculation that WhatsApp may actually be planning VoIP functionality.

Nothing is official yet, but a set of leaked images showcase a voice-calling feature embedded in the world's most popular instant messaging app. If the new rumour is to be believed, the new feature is reportedly being tested before making it available to public.

The leaked screenshots of the purported voice-calling feature in WhatsApp was shared by Androidworld.nl. Based on the screenshots, GSM Arena concluded that the calling functionality will be separated from the chat function, which means there will be a dedicated screen to display call logs, contacts and call status. The speculations also indicate that users may be able to record calls with a built-in feature.

Although, there will be different screens for chat and voice calling features, the screenshots suggest users will be able to see missed calls within the chat screen and start an IM conversation from the call screen. GSM points out that the separation is merely for testing and the final roll-out will be more polished and integrated.

The folks at Androidworld.nl unearthed the features from WhatsApp's web version, which is usually updated more frequently than the Google Play version. The company tests new features with the web version before officially setting them free into the official app. The voice-calling feature is a prominent upgrade for WhatsApp as the developers of the app have ensured the roll-out sometime in Q1 2015. The new leak makes complete sense as the company might be putting the feature through some final tests.

Currently, there is no exact timeline for the feature's roll-out but it will be a great addition. In India, more than 70 million smartphone users use WhatsApp for messaging friends, family and colleagues. Voice-calling will not only bring a feasible solution to Indians but it will also help WhatsApp attract users of rival apps like Line, Skype and Viber.

There are conflicts on whether WhatsApp will charge customers for using the voice-calling feature but it is highly unlikely.